[cfe-dev] [RFC] Make "requires arm" also include AArch64 in module map files

[Tim Northover]

On 28 Jul 2015, at 06:32, Ben Langmuir <blangmuir at apple.com> wrote:
> Do you have any thoughts on the specific target feature names for module maps I’m proposing (changing “arm” to include AArch64 and adding “arm32”)?  As I’ve said, my own (naive) expectation was that “arm” would include “AArch64”, and I was surprised when that wasn’t the case.

I agree, "arm" is the one I was most happy with. What we're doing is based on the ARM ACLE document, which covers both AArch32 and AArch64. The underlying architectures are different, but the whole point of this union (and the modules it's being used to implement) is that the programmer shouldn't have to care. It's also the preferred catch-all term by ARM the company. There's just no viable alternative that I can see for the union.

For me, it gets murky when we think about the 32-bit and 64-bit only variants:

  + arm/arm64 and arm/aarch64 are out because of the top-level choice.
  + aarch32/aarch64 would probably be ideal for me, but aarch32 hasn't really caught on elsewhere
  + arm32/arm64 is also possible, especially as Apple are going to be the main consumers.

Anyway, that's my preferred shade of fuschia. Orange spots are also an option.

Cheers.

Tim.